Diacryloxy esters of anhydrides and coating compositions derived therefrom

ABSTRACT

This invention relates to acryloxy (or methacryloxy)-alkyl (or alkyloxyalkyl) acryloxy (or methacryloxy) hydroxyalkyl organic dicarboxylic esters prepared by reacting an organic acid anhydride with a hydroxyalkyl acrylate or methacrylate and then reacting this half-ester with a glycidyl acrylate or methacrylate. These compounds are useful in coating compositions and particularly coating compositions curable by radiation.

Parker et al.

DIACRYLOXY ESTERS OF ANHYDRIDES AND COATING COMPOSITIONS DERIVEDTHEREFROM Inventors: Gordon M. Parker, Harwick; Marco Wismer, Gibsonia;Ernest A. Hahn, Pittsburgh, all of Pa.

Assignee: PPG Industries, Inc., Pittsburgh, Pa.

Filed: Apr. 8, 1969 Appl. No.: 814,436

References Cited UNITED STATES PATENTS 9/l945 Muskat et al. 260/89.5 X

[ 1 Jan. 15, 1974 2,951,758 9/1960 Notley 260/89.5 X 3,221,043 11/1965Fekete et al.. 260/475 UN 3,336,418 8/1967 Dill 260/475 UN X 3,367,9922/1968 Bearden 260/475 UN X 3,455,801 7/1969 DAlelio 204/15922 X3,485,733 12/1969 DAlelio 204/l59.22 X

Primary Examiner-William D. Martin Assistant ExaminerJohn H. NewsomeAtt0rney-Chish0lm and Spencer 5 7] ABSTRACT This invention relates toacryloxy (or methacryl0xy)- alkyl (or alkyloxyalkyl) acryloxy (ormethacryloxy) hydroxyalkyl organic dicarboxylic esters prepared byreacting an organic acid anhydride with a hydroxyalkyl acrylate ormethacrylate and then reacting this half-ester with a glycidyl acrylateor methacrylate. These compounds are useful in coating compositions andparticularly coating compositions curable by radiation.

30 Claims, No Drawings DIACRYLOXY ESTERS OF ANHYDRIDES AND COATINGCOMPOSITIONS DERIVED THEREFROM where is the residual moiety of anorganic dicarboxylic acid anhydride of the formula:

where Ra R contains two to carbon atoms, x being a whole number from 1through 9, y being a whole number from I through 5 and where R R R and Rare selected from the group consisting of hydrogen and lower alkyl; andwhere R, and R are selected from the group consisting of hydrogen andmethyl, preferably hydrogen, produce excellent radiation curable coatingcompositions.

The above compounds are prepared by reacting, in a first stage, anorganic acid hydride with a hydroxyalkyl acrylate or methacrylate toform a half-ester. The resultant half-ester is then reacted with aglycidyl acrylate or methacrylate in a second stage to form thehydroxyl-containing unsaturated compounds of the formula above.

Virtually any monomeric unsubstituted anhydride may be employed in thereaction. Anhydrides bearing substituents which do not totally interferewith the anhydride ring opening or the subsequent reaction between thehalf-ester and glycidyl compound may likewise be employed. Examples ofsuch groups include halogen, for example, bromine, chlorine and fluorineand nitrile. Preferably, the anhydride employed is a vicinal anhydride.

Examples of such anhydrides include anhydrides of the formulas:

ll R37 0 dride, endomethylene tetrahydrophthalic anhydride, chlorendicanhydride, itaconic anhydride, citraconic anhydride, maleic anhydride,dichloromaleic anhydride, chloromaleic anhydride, ethyl maleicanhydride, dimethyl maleic anhydride, and others.

The hydroxyalkyl acrylate or methacrylate which may be employed in thefirst stage reactions includes any hydroxy-alkyl acrylate of theformula:

where R R R and R are selected from the group consisting of hydrogen andlower alkyl and R is selected from the group consisting of hydrogen andmethyl, preferably hydrogen, and where x is a whole number from 1through 9 and y is a whole number from 1 through 5, the group R3 R lt-(i);

containing from 2 to 10 carbon atoms.

Specific examples of such compounds include: hydroxyethyl acrylate,hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropylmethacrylate, hydroxyethoxyethyl acrylate, hydroxypropoxypropoxypropylacrylate.

The glycidyl compound which may be used in the second stage is selectedfrom the group consisting of glycidyl acrylate and glycidylmethacrylate.

The compounds of the invention include 2- acryloxyethyl3-acryloxy-2-hydroxypropyl phthalate, 2-methacryloxyethyl3-methacryloxy-2-hydroxypropyl phthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl tetrahydrophthalate, 3-acryloxypropyl3-acryloxy-2- hydroxypropyl hexahydrophthalate, 2-acryloxypropyl3-acryloxy-2-hydroxypropyl hexachlorophthalate, 2(2-acryloxyethoxy)ethyl3-acryloxy-2-hydroxypropyl chlorendate, 2-acryloxyethyl 3-acryloxy-2-hydroxypropyl maleate, 3 3-hydroxypropoxypropoxy propyl3-acryloxy-2-hydroxypropyl chloromaleate, and 2-acryloxyethyl3-acryloxy-2-hydroxypropyl citraconate.

As stated previously, the process for preparing the compounds of thisinvention is a two-stage process.

The first stage is conducted by charging the organic acid anhydride andhydroxyl acrylic compound into a reaction vessel and mixing to open theanhydride ring to form a half-ester.

The temperature at which the ring opening may be conducted can be variedwidely, however, the reaction proceeds at room temperature, preferably,the reaction mixture is heated, usually to between about 70 and 120C.,although temperatures as high as 150C. or higher may be employed,depending on the stability of the reactants or the acceptability oflower yield due to side reactions.

The proportion of the reactants is not critical; however, to obtainmaximum conversion with maximum purity, a mole ratio approximating 1:1,for example, a mole ratio between about 0.7 and about 1.3 is desirable.The anhydride may be present in molar excess without substantialreaction. Molar excesses of the hydroxy compound may reduce the yield;however, molar excesses approaching 2:1 will still produce the desiredproduct.

The reaction may be conducted in bulk, or, if desired, in the presenceof an inert aromatic or polar organic material solvent such as, forexample, dimethyl formamide, a polyethylene glycol dimethyl ether,ketones, toluene, xylene, and the like.

The first stage reaction is usually conducted in the absence of acatalyst; however, if desired, a catalyst for anhydride ring opening maybe employed.

The second stage reaction is conducted by adding the glycidyl compoundto the product of the first stage reaction. While it is possible toconduct the reaction by mixing the reactants, it is desirable to add theglycidyl compound incrementally so as to better control the reaction andto obtain higher yields of the desired product.

Again, in the second stage, the proportions of the reactants are notcritical; however, to obtain maximum conversion with maximum purity, amole ratio of approximately lzl, for example, in the range of about 0.7to about 1.3 moles, is desirable. The half-ester may be present in amolar excess without substantial reaction. Molar excess of the glycidylcompound may reduce the yield; however, excess of less than 2 moles willstill produce the desired product.

While the reaction is usually conducted in bulk, it is possible toconduct the second stage reaction in the presence of an aromatic orinert polar material solvent such as described above.

The temperature at which the second-stage reaction is conducted issubject to wide variation. While the reaction proceeds at roomtemperature, it is desirable to heat the reaction mixture, usually to atemperature of about C. to about C. Temperatures as high as C. or highermay be employed, depending on the stability of the reactants andproducts employed; however, these higher temperatures tend to increaseside reactions and therefore reduce the yield of desired product.

While the use of a catalyst is not essential in the second stagereaction, it is desirable to employ an amine catalyst such as N-methylmorpholine.

Since the process has at least one reactant in each step containingpolymerizable unsaturation, it is desirable, although not absolutelynecessary, to employ an inhibitor in the reaction mixture, for example,a quinone, a hydroquinone, or a phenolic inhibitor of the typeconventionally employed with unsaturated acrylic-type monomers. Examplesof inhibitors include quinone, hydroquinone, methyl quinone and methylhydroquinone and the dimethyl ether of hydroquinone.

The compounds hereinabove disclosed are particularly useful in thepreparation of coating compositions which may be cured by ionizingradiation, that is, UV light electron beams and nuclear radiation.

The particular method used to coat the substrate is not critical as anyconventional coating technique may be used. For instance, spraying,roller coating, curtain coating, and many other well-known methods maybe used. Using the monomers of the present invention, it is preferableto apply the coating using a roller coater to achieve thin uniformcoatings.

The term irradiation, as used herein, means high energy radiation and/orthe secondary energies resulting from conversion of this electron orother particle energy to neutron or gamma radiation, said energies beingat least equivalent to about 100,000 electron volts. While various typesof irradiation are suitable for this purpose, such as X-ray and gammaand beta rays, the radiation produced by accelerated high energyelectrons has been found to be very conveniently and economicallyapplicable and to give very satisfactory results. However, regardless ofthe type of radiation and the type of equipment used for its generationor application, the use thereof in the practice of the invention asdescribed herein is contemplated as falling within the scope of thisinvention so long as the ionization radiation is equivalent to at leastabout 100,000 electron volts.

While there is no upper limit to the electron energy that can be soapplied advantageously, the effects desired in the practice of thisinvention can be accomplished without having to go to above about 20million electron volts. Generally, the higher the electron energy used,the greater is the depth of penetration into the massive structure ofthe'materials to be treated. For other types of radiation, such as gammaand X-rays, energy systems equivalent to the above range of electronvolts are desirable.

It is intended that the term irradiation include what has been referredto in the prior art as ionizing radiation which has been defined asradiation possessing an energy at least sufficient produce ions or tobreak chemical bonds and thus includes also radiations such as ionizingparticle radiation as well as radiations of the type termed ionizingelectromagnetic radiation.

The term ionizing particle radiation has been used to designate theemission of electrons or highly accelerated nuclear particles such asprotons, neutrons, alphaparticles, deuterons, beta-particles, or theiranalogs, directed in such a way that the particle is projected into themass to be irradiated. Charged particles can be accelerated by the aidof voltage gradients by such devices as accelerators with resonancechambers, Van der Graaff generators, betatrons, synchrotons, cyclotrons,etc. Neutron radiation can be produced by bombarding a selected lightmetal such as beryllium with positive particles of high energy. Particleradiation can also be obtained by the use of an atomic pile, radioactiveisotopes or other natural or synthetic radioactive materials.

Ionizing electromagnetic irradiation is produced when a metallic target,such as tungsten, is bombarded with electrons of suitable energy. Thisenergy is conferred to the electrons by potential accelerators of over0.1 million electron volts (mev.). In addition to irradiation of thistype, commonly called X-ray, an ionizing electromagnetic irradiationsuitable for the practice of this invention can be obtained by means ofa nuclear reactor (pile) or by the use of natural or syntheticradioactive material, for example, cobalt 60.

Various types of high power electron linear accelerators arecommerically available, for example, the ARCO type traveling waveaccelerator, Model Mark I, operating at 3 to million electron volts,such as supplied by High Voltage Engineering Corporation, Burlington,Mass, or other types of accelerators as described in U. S. Pat. No.2,763,609 and in British Patent No. 762,953 are satisfactory for thepractice of this invention.

The monomers described herein will cure acceptably using any totaldosage between about 2 megarads and about 20 megarads. A rad is definedas that amount of radiation required to supply ergs per gram of materialbeing treated and a megarad is 10 rads. The total dosage is the totalamount of irradiation received by the coating or film. The rate ofirradiation is generally not believed to be important as the totaldosage is believed to be the predominant factor in the curing of themonomers.

The process of this invention is best carried out by applying a layer offrom about one mil to about 25 mils thickness over a substrate andpassing the coated substrate under electron beam irradiation at acertain line speed for a designated time. The particular speed and timeis not critical so long as the coated substrate is exposed to theirradiation for a time long enough to acquire a total dose of about 2 toabout 20 megarads. The line speed used may be varied according toapparatus limitations. However, it is desirable that the line speed befast enough so that the monomer mixture will not flow off the substrateduring curing. It is noted that at a total dosage of less than about 2megarads there is generally insufficient polymerization of the monomersand at a total dosage exceeding about 20 megarads there is generallysome waste of energy. The preferred range of total dosage is betweenabout 2 megarads and 10 megarads. The irradiation is preferably carriedout in an inert atmosphere, such as nitrogen gas.

The compounds per se when in liquid form are susceptible topolymerization to form coatings or shaped articles. However, thecompounds of the invention may likewise be admixed with other monomersin order to control viscosity and other application variables such asrate of cure as well as final film properties such as hardness andflexibility. The presently preferred monomer utilized to controlviscosity is butyl acrylate. Other reactive monomers, in addition toacrylic and methacrylic acid, include acrylic or methacrylic esters ofalkanols containing from about four to about 18 carbon atoms. Theseacrylic monomers generally have the formula:

where R is selected from the group consisting of H and CH radicals andR, is an alkyl radical having from four to 18 carbon atoms. The alkylradical R, may be a branched or straight chain radical. Examples ofthese monomers are butyl acrylate, butyl methacrylate, 2- ethylhexylacrylate, lauryl acrylate, amyl methacrylate, n-octyl acrylate, isooctylacrylate, isodecyl methacrylate, 2,4,4-trimethyl-2-pentyl acrylate,2,4,4-trimethyl- 2-pentyl methacrylate, methyl acrylate, ethyl acrylate,isobutyl acrylate, 2-ethylhexylacrylate, isobutyl methacrylate,hydroxyethyl acrylate, hydroxypropyl acrylate, t-butylaminoethylacrylate, stearyl methacrylate, silane methacrylate, butyl cellosolveacrylate, cyclohexyl acrylate, n-decyl acrylate, n-decyl methacrylate,2-ethoxy methacrylate, 2-ethylhexyl methacrylate, octadecyl acrylate,oleyl methacrylate, tetrahydropyranyl methacrylate, tridecylmethacrylate, 2,4,4-trimethyl pentane diol isobutyrate, 3-methaerylate,and the like.

In addition to the acrylic monomers, the monomer mixtures utilizedcontain one or more functional monomers which are compatible with'theabove-described acrylic monomers. These monomers are ethylenicallyunsaturated monomers containing a reactive functional group and areadded to the acrylic monomers to modify the resultant coating and toincorporate crosslinking sites. The preferred modifying monomers havethe forwhere R is selected from the group consisting of H and CH and Ris selected from the group consisting of OH; Nl-l CH: NHR NHCH OR OCHzCHOH; OCHzCH X; NH-CI-IzCOCHa;

I l t CH:

CH; OCIhCHiCN; OR; R ORBO; R5(CHIO3); OCHfl LCI-I O; C(CHgO);

NHR NH and NR NR R is selected from the group consisting of H, COORCOOH, and CONHR and R is an alkyl radical having from one to 12 carbonatoms and X is selected from the group consisting of chlorine, fluorineand bromine and n is a whole number from 1 to 4.

Examples of the unsaturated monomers having functional groups which arethe preferred modifying functional monomers are N-butoxymethylacrylamide; N- butoxymethyl methacrylamide; diethylene glycoldiacrylate; 2-hydroxyethyl acrylate; 2-cyanoethyl acrylate; acrylicacid; diacetone acrylamide; 2-acryloxyethyl hydrogen maleate;2-acryloxyethyl hydrogen phthalate; 2-acryloxyethyl hydrogen succinate;2- methacryloxyethyl hydrogen maleate; 2-cyanoethyl hydrogen maleate;2-acryloxyethyl hydrogen chlorendate; N-t-butylacrylamide; N-iospropylacrylamide; N- (2,4,4,-trimethyl-2-pentyl)acrylamide; hydroxypropylacrylate; 2-hydroxybutyl acrylate; ethyl hydrogen maleate; ethylhydrogen fumarate, and the like. Others include 1,3-butylene glycoldiacrylate, 1,4- butane diol diacrylate; 1,4-butane diol dimethacrylate;l,l0-decamethylene glycol dimethacrylate; diallyl itaconate; diethyleneglycol dimethacrylate; glyceryl trimethacrylate; 1,6-hexane dioldiacrylate; 1,6-hexane diol methacrylate; 2,2-dimethyl propanediacrylate (neopentyl glycol diacrylate); 2,2-dimethyl propanedimethacrylate (neopentyl glycol dimethacrylate); polyethylene glycol(200) diacrylate; tetraethylene glycol diacrylate; triethylene glycoldiacrylate; 3,5,5- trimethylhexyl acrylate; 3,5,S-trimethylhexylmethacrylate (isononyl methacrylate); 2,2,4-trimethyl-l,3- pentane dioldimethacrylate; trimethylol ethane trimethacrylate; trimethylol propanediallyl ether monomethacrylate; tripropylene glycol dimethacrylate;trimethylol propane triacrylate; and the like.

Any one or combination of two or more of the above functional monomersmay be included in the mixture of monomers.

It is often desirable to add small amounts of a thickening agent toincrease the viscosity of the monomer mixture and to facilitate theapplication of the monomer mixture to a substrate. The preferredthickening agents are relatively high molecular weight polymericmaterials. By high molecular weight is meant molecular weights which aregreater than about 20,000. When present, the polymeric thickening agentsgenerally comprise up to about 30 percent by weight of the mixture to besubjected to the ionizing irradiation but are preferably present in anamount of from about 3 to about 30 percent by weight of the mixture.Examples of these thickening agents are neoprene rubbers, butyl rubbers,styrene-butadiene rubbers, nitrile rubbers poly(ethylene),poly(propylene), copolymers of ethylene and vinyl esters or ethers,poly(alkyl acrylates), poly(alkyl methacrylates), polyesters such aspoly(ethylene maleate), poly(propylene fumarate), poly(propylenephthalate), and the like.

Other types of thickening agents may also be used to good advantage.These include finely divided silica, alumina, and the like.

A particularly useful formulation has been found to comprise percent of2-acryloxyethyl-3-acryloxy-2- hydroxypropyl phthalate, 15 percent butylacrylate and 10 percent 1,4-butandiol diacrylate. This formulationshowed stain resistance, excellent adhesion to hardboard and excellentgloss and color retention as a clear coating (one mil film thickness)when cured by an electron beam of 300-500 KV with a total dose of 3-4Megarads.

In the above and similar formulations, the 2-acryloxyethyl-3-acryloxy-2-hydroxypropyl phthalate may be replaced byany compound of the invention as set forth above to obtain a use coatingcomposition which may be radiation cured.

The compounds of the invention and formulations containing them arerelatively dose rate independent within practical limits. Generally, atotal dose of 3-4 Megarads is sufficient to cure coatings containing thecompounds of the invention. However, total doses as high as 20 Megarads,or even many fold higher, do not appear to have a detrimental effect onthe film. Obviously, however, economical consideration dictates thelowest total dose necessary to cure the films, which amount may readilybe determined.

The amount of compound as defined above which may be employed in thecoating composition of the invention ranges from percent to 5 percent bywhich the remainder being radiation-active monomers or diluents such asmonomer-soluble inert or reactive polymers.

sition should be in liquid form and the ingredients and proportionsshould be chosen with this in mind.

For speed of cure and quality of the cured film, it is highly preferablethat the curing of the above compositions be carried out in an inertatmosphere such as nitrogen, helium, argon, etc.

There are set forth below several examples which illustrate the methodsof producing the compounds of the invention and their use in coatingcompositions. These examples are, of course, given by way ofillustration only and should not be construed as limiting the inventionto the particular details thereof. All parts and percentages set forth,as is true throughout the specification, are by weight unless otherwisespecified.

EXAMPLE 1 Into a reactor were charged 296.2 parts of phthalic For easeof application and curing, the above compoanhydride and 236.8 parts ofhydroxyethyl acrylate, along with 0.2 parts of hydroquinone. Thereactants were charged in the following manner. The hydroxyethylacrylate containing the hydroquinone was first heated to 80C. and thephthalic anhydride gradually added and dissolved. The reaction mixturewas then heated to 90-100C. for 2% hours. The reaction mixture was thenheated to a temperature of 110C. and 258.8 parts of glycidyl acrylatecontaining 0.1 parts of n-methyl morpholine were added dropwise, thetemperature of the reaction mixture being maintained at 1 C. forone-half hour after the addition was completed. The final reactionmixture contained a compound corresponding to the formula:

EXAMPLE II Into a reactor were charged 171 parts of hydroxyethylmethacrylate and 0.3 part of hydroquinone. This mixture was heated to7080C. To the above heated mixture was added 200 parts of phthalicanhydride gradually until all the anhydride had dissolved. The mixturewas then heated between 90l00C. for 2% hours and to the reaction mixturewas then added 192 parts of glycidyl methacrylate containing 0.5 partsof n-methyl morpholine. The glycidyl methacrylate was added dropwise,maintaining the reaction mixture at 100110C. The reaction mixture washeld at 110C. for one-half hour after addition was completed. Theproduct had a formula:

EXAMPLE Ill glycidyl actylate containing 0.1 part of n-methylmorpholine. The reaction was conducted at 110C. and the reaction mixturewas held at this temperature during the reaction and for one-half hourafter the glycol acrylate addition was completed. The product of thereaction was 2-acryloxyethyl 3-acryloxy-2-hydroxypropyl maleate.

EXAMPLE 1V Into a reactor were charged 92.8 parts of hydroxyethylacrylate containing 0.1 part of hydroquinone. The mixture was heated to50C. and 297 parts of chlorendic anhydride were gradually added and themixture stirred until solution was obtained. The mixture was then heatedto a temperature of -90C. and held at this temperature for 2% hours. Aclear, slightly yellow solution results, having on cooling aGardner-Holdt viscosity of about Z.

To 124 parts of the above reaction mixture, heated to 110C. there wasadded dropwise 38.5 parts of glycidyl acrylate containing 0.1 part ofn-methyl morpholine. The dropwise addition required approximately 1hour. The temperature was kept between 1 l0-125C. After the addition wascomplete, this temperature was maintained for an additional half hour.The product of the reaction was 2-acryloxyethyl 3-acryloxy-2-hydroxypropyl chlorendate.

EXAMPLE V Into a reactor were charged 154 parts of hexahydrophthalicanhydride and l 16 parts of hydroxyethyl acrylate, along with 0.4 partof hydroquinone. The mixture was heated at C. for 2% hours, at whichtime the reaction temperature was raised to C. and there were added 0.4part of n-methyl morpholine. There was then added to the reactionmixture 153.6 parts of glycidyl acrylate. The glycidyl acrylate wasslowly added over a period of one-half hour, the temperature of thereaction mixture being maintained at 100C. for 1 hour after theradiation was completed. The product of the reaction was 2-acryloxyethyl3-acryloxy-2-hydroxypropyl hexahydrophthalate.

EXAMPLE VI Into a reactor were charged 152 parts of tetrahydrophthalicanhydride, 116 parts of 2-hydroxyethyl acrylate and 0.4 part ofhydroquinone. The reaction mixture was heated to 100C. for 2% hours, atwhich time the reaction temperature was raised to l 10C. and 0.4 part ofn-methyl morpholine was added. 128 parts of glycidyl acrylate was thenadded dropwise over a period of one-half hour and the reactiontemperature was maintained at 110C. for 3 hours after the addition wascomplete. The product of the reaction was 2- acryloxyethyl3-acryloxy-Z-hydroxypropyl tetrahydrophthalate.

EXAMPLE V11 Into a reactor were charged 143 parts of tetrachlorophthalicanhydride, 58 parts of 2-hydroxyethyl acrylate and 0.3 part ofhydroquinone, along with 100 milliliters of toluene. The reactionmixture was heated for 2% hours at 100C. The reaction temperature wasthen raised to 110C. and 0.3 parts of n-methyl morpholine were added tothe reaction mixture. There was then added 64 parts of glycidylmethacrylate dropwise over a period of one-half hour. The reactiontemperature was maintained at l 10C. for 2 hours after the addition wascomplete, at which time the toluene was removed under vacuum. Theproduct of the reaction was 2- acryloxyethyl 3-acryloxy-2-hydroxypropyltetra chlorophthalate.

If desired, the remaining hydroxyl functionality in the compounds of theinvention may be reacted, for example, by acetalation, or otherconventional reaction. Such further modification of the compounds of theinvention does not detract and may enhance their use in coatingcompositions.

EXAMPLE vm The following resin samples were cured on hardboard undernitrogen atmosphere by passing 3 mil wet samples under a 400 KV electronbeam. The total dose in each case was 2.1 Mrads. All samples cured inone pass.

3-acryloxy'2-hydroxypropyl marresiltant film hexahydrophthalate 2.5parts triethylene glycol diacrylate 7.5 parts butyl acrylate 90 parts2-acryloxyethyl 3-acryloxy-2-hydroxypropyl phthalate 2.5 partstriethylene glycol diacrylate 7.5 parts butyl acrylate Hard,marresistant film EXAMPLE IX The following resin samples were cured onhardboard under nitrogen atmosphere by passing a 3 mil wet film under a500 KV electron beam. The total dose was 4.5 Mrads per pass. The samplescured in one pass.

3-acryloxy-2-hydroxypropyl maleate marresistant film 20 parts butylacrylate Similar results are obtained by substituting the correspondingstarting materials to produce the other compounds enumerated. Likewise,the compounds shown in the working samples may be replaced by othercompounds within the scope of the invention to achieve equivalentresults.

According to the provisions of the patent statutes, there are describedabove the invention and what are now considered to be its bestembodiments. However, within the scope of the appended claims, it is tobe understood that the invention can be practiced otherwise than asspecifically described.

We claim:

1. A compound corresponding to the formula:

is the residual moiety of an organic dicarboxylic acid anhydride of theformula:

where contains two to carbon atoms, x being a whole number from Ithrough 9, y being a whole number from 1 through 5 and where R R R and Rare selected from the group consisting of hydrogen and lower alkyl; andwhere R, and R are selected from the group consisting of hydrogen andmethyl.

2. A compound as in claim 1 wherein R and R are hydrogen.

3. A compound as in claim 1 wherein y is l.

4. A compound as in claim 3 wherein R, and R are hydrogen.

5. A compound as in claim 4 wherein R R R and R are hydrogen.

6. A compound as in claim 1 wherein is selected from the groupconsisting of H H H H H H H /H H H- H and H H- H i I H H H H H H H H 12.A method of forming a coating which comprises applying to a substrate acomposition comprising a compound corresponding to the formula:

where where contains two to l carbon atoms, x being a whole hum ber from1 through 9, y being a whole number from 1 through and where R R R and Rare selected from the group consisting of hydrogen and lower alkyl; andwhere R and R are selected from the group consisting of hydrogen andmethyl, and subjecting the coating thus formed to ionizing radiation.

13. A method as in claim 12 wherein R, and R are hydrogen.

14. A method as in claim 12 wherein y is 1.

15. A method as in claim 14 wherein R Rf R and is selected from thegroup consisting of a... H H W 7 H H H H 11 H- 4 H H H H I i 11 H 11 \Hand R, and R are hydrogen.

17. A method as in claim 16 wherein y is l.

18. A method as in claim 17 where R R R and R are hydrogen.

19. A method as in claim 12 wherein the compound is selected from thegroup consisting of 2-acryloxyethyl 3-acryloxy-2-hydroxypropyl maleate,2-acryloxyethyl 3-acryloxy-2-hydroxypropyl phthalate, 2-acryloxyethyl3-acryloxy-Z-hydroxypropyl tetrachlorophthalate, 2- acryloxyethyl3-acryloxy-2-hydroxypropyl chlorendate, 2-acryloxyethyl3-acryloxy-2-hydroxyproply hexahydrophthalate, 2-acryloxyethyl3-acryloxy-2- hydroxypropyl tetrahydropht halate.

20. A method as in claim 12 wherein the composition contains at leastone additional copolymerizable monomer.

21. A method as in claim 13 wherein the composition contains at leastone additional copolymerizable monomer.

22. A method as in claim 15 wherein the composition contains at leastone additional copolymerizable monomer.

23. A method as in claim 16 wherein the composition contains at leastone additional copolymerizable monomer.

24. A method as in claim 18 wherein the composition contains at leastone additional copolymerizable monomer.

25. A method as in claim 19 wherein the composition contains at leastone additional copolymerizable monomer.

26. The coated article formed by the method of claim 12.

27. The coated article formed by the method of claim

2. A compound as in claim 1 wherein R7 and R8 are hydrogen.
 3. Acompound as in claim 1 wherein y is
 1. 4. A compound as in claim 3wherein R7 and R8 are hydrogen.
 5. A compound as in claim 4 wherein R3,R4, R5 and R6 are hydrogen.
 6. A compound as in claim 1 wherein
 7. Acompound as in claim 6 wherein R7 and R8 are hydrogen.
 8. A compound asin claim 6 wherein y is
 1. 9. A compound as in claim 8 wherein R7 and R8are hydrogen.
 10. A compound as in claim 9 wherein R3, R4, R5 and R6 arehydrogen.
 11. A compound as in claim 1 selected from the groupconsisting of 2-acryloxyethyl 3-acryloxy-2-hydroxypropyl maleate,2-acryloxyethyl 3-acryloxy-2-hydroxypropyl phthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl tetrachlorophthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl chlorendate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl hexahydrophthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl tetrahydrophthalate.
 12. A method of forminga coating which comprises applying to a substrate a compositioncomprising a compound corresponding to the formula:
 13. A method as inclaim 12 wherein R7 and R8 are hydrogen.
 14. A method as in claim 12wherein y is
 1. 15. A method as in claim 14 wherein R3, R4, R5 and R6are hydrogen.
 16. A method as in claim 12 wherein
 17. A method as inclaim 16 wherein y is
 1. 18. A method as in claim 17 where R3, R4, R5and R6 are hydrogen.
 19. A method as in claim 12 wherein the compound isselected from the group consisting of 2-acryloxyethyl3-acryloxy-2-hydroxypropyl maleate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl phthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl tetrachlorophthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl chlorendate, 2-acryloxyethyl3-acryloxy-2-hydroxyproply hexahydrophthalate, 2-acryloxyethyl3-acryloxy-2-hydroxypropyl tetrahydrophthalate.
 20. A method as in claim12 wherein the composition contains at least one additionalcopolymerizable monomer.
 21. A method as in claim 13 wherein thecomposition contains at least one additional copolymerizable monomer.22. A method as in claim 15 wherein the composition contains at leastone additional copolymerizable monomer.
 23. A method as in claim 16wherein the composition contains at least one additional copolymerizablemonomer.
 24. A method as in claim 18 wherein the composition contains atleast one additional copolymerizable monomer.
 25. A method as in claim19 wherein the composition contains at least one additionalcopolymerizable monomer.
 26. The coated article formed bY the method ofclaim
 12. 27. The coated article formed by the method of claim
 13. 28.The coated article formed by the method of claim
 16. 29. The coatedarticle formed by the method of claim
 19. 30. The coated article formedby the method of claim 20.